Shape memory alloys (SMA) are a class of materials exhibiting pseudo-elasticity and shape memory. Deformation of an SMA element such as an SMA wire is temporary and reversible by application of an external stimulus such as heat or an electrical signal. Shape memory capabilities of an SMA element are due in large part to a temperature- and stress-dependent solid-state change of phase that occurs due to a cooperative atomic rearrangement.
Certain mechatronic applications use SMA elements to carry and transmit a load and/or a displacement, for example SMA wire-based control actuators. However, solder materials of the types conventionally used to join conductive wires in electronic devices do not bond well to SMA materials such as nickel-titanium. Therefore, current practices for joining SMA elements to a component include crimping a metal end attachment onto the distal ends of the SMA element and then fastening the crimped end attachment to a surface of the component. However, the crimping of an SMA element has certain performance limitations, including potential slippage or fatigue over time at or adjacent to the crimped end attachments.